| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique precisely estimating an amount of extension of a ball screw and precisely compensating a positional displacement of a movable portion. SOLUTION: Based on moving speed of the movable portion detected as an existing section of the moving portion identified during the unit measuring time, (1) the total compensation speed is calculated by using the total summing up speed of the movable portion passing through during a unit measuring time and a time constantτon each section. (2) The position of the gravity center of a two-dimensional range formed by a line of the section and the total compensation speed is identified, and the distance G from an origin point to the center of its gravity is calculated. (3) An area Q of the two-dimensional range is calculated. (4) A coefficient for determining an approximate expression about at least three points among the vicinity of the origin point, the vicinity of an intermediate point, and the vicinity of a terminal point is calculated. (5) An amount of a position gap of the movable portion at the three points is calculated by making use of the area Q and the distance G at the time of an actual operation. (6) An amount of a position gap at the whole moving range of the movable portion is calculated by making use of secondary interpolation. (7) Then, an amount of pitch error compensation is modified by the amount of the position gap of the movable portion. COPYRIGHT: (C)2009,JPO&INPIT
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